BROCKTON – Police Chief Robert Hayden is slated to take about a $100,000 pay cut after the Boston Retirement Board informed the city that he would not be able to freeze his pension while heading the Brockton Police Department.

Hayden, who served in the Boston Police Department for 28 years, had planned to freeze his pension after taking the position, but the board informed the city last week that Hayden would not be able to maintain his health insurance if his pension was frozen.

Under the terms of his original interim chief contract, Hayden was slated to receive an annual salary of $149,000 and reimbursement for 75 percent of the monthly premium for his health plan.

The contract has since been amended so that Hayden will receive $51,600 in compensation annually with no reimbursement for medical insurance.

The amendment is due to a state law that prohibits a retiree from collecting a yearly salary from a state agency or municipality that, when added to their annual retirement allowance, exceeds the current yearly salary for the position from which they retired.

State law also prohibits retirees collecting a state or municipal pension from working more than 960 hours in a year.

However, Bob Buckley, Mayor Bill Carpenter’s chief of staff, said he does not expect that the new arrangement will have any impact on Hayden’s ability to perform his duties as chief.

“With a chief or a commissioner, their schedule is basically their own anyway, and they are on-call 24 hours a day,” Buckley said. “I don’t really see him changing the amount of effort or time that he’s going to be spending in Brockton.”

Hayden is currently working on a 60-day interim contract, which he began on Jan. 31.

A similar amendment is expected to be made to an ordinance that is pending before the City Council’s Ordinance Committee, which would create a civilian police commissioner position to head the department.

If the ordinance is passed, Carpenter has already stated his intention to make Hayden the city’s first police commissioner.

An Ordinance Committee hearing is scheduled for 6 p.m. today to continue debate on the proposed commissioner ordinance.